1. Field of the Invention
The present invention relates in general to a driving circuit of a turntable motor in microwave oven, and more particularly to a driving circuit for driving a turntable motor which is operated at a low voltage.
2. Description of the Prior Art
Generally, microwave ovens utilize microwaves when cooking food. In other words, when the microwaves are applied to food molecules in the water and other frictional heat is generated therefrom. As a result, the food is heated by the frictional heat.
The microwaves are generated by a magnetron which performs an oscillating operation at a fundamental frequency. FIGS. 7 and 8 show such a microwave oven for performing a cooking operation by heating the food with the microwaves generated by the magnetron. As shown in this drawings, the microwave oven includes a magnetron 20, a high voltage transformer 10 (hereinafter referred to as HVT) connected to the magnetron 20 for applying a high voltage to the magnetron 20, a lamp for lighting an inside of a cooking chamber 40, a turntable motor 50 for rotating a turntable 60 so that food can be evenly cooked during the operation of the magnetron 20, a fan motor 80 for cooling the magnetron 20 and circulating air in the cooking chamber 40 during the operation of the magnetron 20. Referring to FIG. 8, also included is a relay 120 and a relay 130 which are turned on/off to control an alternating current (referred to hereinafter as AC) power supplied to a lamp (not shown), a turn turntable motor 50, a fan motor 80, and the like.
Unexplained reference number 110 is a switch for stopping the operation of the magnetron 20 when a microwave door (not shown) is open.
However, there is a problem in the conventional microwave oven according to the prior art thus constructed, in that the turntable motor driving circuit is designed only for receiving a commonly used AC power supply, thereby necessitating an unnecessary large turntable motor, so that production costs and power consumption are increased.